This invention relates to transmissioner mechanisms and more particularly, to means utilizing a velocity control drive for obtaining accurately controlled repetitive cycles of operations.
In many machine applications, it is necessary to perform work functions on a product as it is moved continuously at relatively high speed through a machine. During the portion of the cycle time in which the work function is being performed, it is frequently essential that the machine element in contact with the product be transported at the precise velocity of the product.
Examples of operations of this nature include the heat sealing, cutoff and labeling functions of bag making or packaging machinery. Another example is a flying cutoff in plastic extrusion machinery or, more specifically, a wire harp cutoff for the cutting of continuously moving stacked endless ribbons of processed cheese into desired lengths of finished product.
For practical and economic reasons, it is preferable that the velocity of the work element during its contact time with the product be adjustable to accommodate a range of product sizes or spacing. A stepless adjustment over a broad range is also desirable.
Features of the nature just described are not ordinarily available in relatively simple and inexpensive machines, but the importance and utility of such a mechanism for the packaging industry and for similar applications is quite apparent.